refs #9184. Test point detector position correction.
refs #9184. Employ and test position correction multidetector
refs #9184. Merge branch 'master'

Merge branch 'master' into feature/9184_correct_positions_rro

Conflicts:
	Code/Mantid/Framework/Algorithms/src/ReflectometryReductionOne.cpp
refs #9184. Unused var removed.
Merge remote-tracking branch 'origin/feature/9184_correct_positions_rro'